1. Field of Invention
The present invention relates to rotary grinders and more particularly to laminated rotary grinders and their fabrication.
2. Prior Art
Rotary grinders for abrading metal, bricks, stones and the like are well known in the art. Such rotary grinders typically consist of a single grindstone with a thickness in excess of one inch (2.54 cm). It is also known in the art that a grinder comprising thin laminated grindstone discs produces better grinding efficiency than one made up of a single thick grindstone. This is disclosed, for example, in U.S. Pat. Nos. 2,396,505, 3,023,551, or 3,653,858.
The superior efficiency of laminated rotary grinders is due to the fact that currents of air occur in the space gaps between the thin grindstone disc powdery dust from clogging the grindstone surfaces. The air currents also increase the heat dissipation such that damage to blades and other materials being ground due to generated heat is avoided and the sharpness of such blades can always be maintained. Moreover, the side slipping action of the grinder to eliminate ridges left on the grinding surface by the grinder also contributes to improved grinding efficiency. However, while the prior art laminated grinders are more efficient than the single type rotary grinders, the peak efficiency of such grinders has not been achieved by the prior art laminated rotary grinders.